Small bumps under the skin on the chin are usually the result of folliculitis or sebaceous cysts. They can be treated with medication or surgery. 1. Folliculitis: Folliculitis is usually caused by high temperature, excessive sweating and lack of attention to hygiene. It is characterized by red pimples of rice grain size with pointed tips, accompanied by pustules in severe cases, which can be painful. Erythromycin ointment, fusidic acid cream, clindamycin gel and other drugs can be used under the guidance of the doctor for treatment. 2. Epidermoid cysts: Epidermoid cysts are spherical, solitary or multiple, varying in size, smooth surface, no fluctuation. Surgical excision is the more common method. After surgery, it should be noted that do not scratch arbitrarily, so as not to cause infection. 3. Dermatofibroma: It is a kind of lesion that occurs when the skin damage triggers the proliferation of fibrous tissues, which is often manifested as a single round or oval solid nodule, showing reddish-brown, yellowish-brown or blackish-brown color, etc. There is usually no conscious symptom. Generally no conscious symptoms, no treatment, if necessary, can be surgically removed. Small bumps under the chin may also be caused by other reasons, it is recommended that when uncomfortable symptoms occur, timely medical treatment.